This invention pertains to an adjustable roller mechanism for a sliding closure which provides for a smooth and precise vertical adjustment with a smooth rotational motion and which can be adjusted under load conditions and is automatically self-locking in any position of adjustment.
Prior patents show many different types of adjustable roller mechanisms for sliding closures or similar uses. U.S. Pat. No. 3,826,044, owned by the assignee of this application, shows such a structure with a pivotally-mounted roller bracket adjustable through the action of a rotatable threaded member acting against a cam.
U.S. Pat. No. 3,100,316 shows a pivotally-mounted roller bracket wherein the adjusted position of a pivoted roller bracket is controlled by a rotatable shaft having an eccentric.
U.S. Pat. No. 3,237,238 shows an adjustable roller assembly wherein a rotatable cam with a stepped surface provides for stepped adjustment of a roller bracket relative to a case and with the steps on the cam providing for locking of the cam at any one of said stepped positions.
None of the above patents provide an adjustable roller mechanism utilizing a smooth surfaced cam to permit precise vertical adjustment and the other advantages provided by the invention disclosed herein and as set forth below.